This invention relates generally to an electrostatographic reproducing machine for reproducing an original document on a copy sheet. More particularly, the reproducing machine of the present invention includes a combined charging-transferring station, a combined exposing-discharging station, and a combined developing-cleaning station.
Generally, in the process of electrophotographic printing, a photoconductive member is charged to a substantially uniform potential to sensitize the surface thereof. The charged portion of the photoconductive surface is exposed to a light image of an original document being reproduced. This records an electrostaic latent image on the photoconductive member corresponding to the informational areas contained within the original document. After recording the electrostatic latent image on the photoconductive member, the latent image is developed by bringing a developer material comprising carrier granules having toner particles adhering triboelectrically thereto into contact therewith. The toner particles are attracted from the carrier granules to the electrostatic latent image to form a toner powder image which is subsequently transferred to a copy sheet. Thereafter, the toner powder image is permanently affixed to the copy sheet in image configuration.
Generally, the various stations for charging, exposing, developing, transferring, cleaning, and discharging are separate units disposed about the photoconductive member. The complexity and associate cost of the reproducing machine may be significantly reduced if the various separate units are combined to perform dual functions. Hereinbefore, various attempts have been made to achieve the foregoing. In particular, various combination units have been devised for electrophotographic printing machine employing photoconductive drums.